OK, let's take a couple of steps back, & take a measured approach to the problem - it's got you a little bit wired, & you're kind of "shotgunning" guesses all over the place.

First - All of the major parts places (that I'm aware of) will let you either rent/borrow a code reader, or will go out into the parking lot with you & plug the reader in & pull codes for you. If you can't afford the $80 or so that's needed to buy a basic code reader, then call around & see if you can rent/borrow one. Failing that, you might need to drag the car to them... Write down what the codes are!

Next - go out & get a "noid light" for the LS-style injectors & a digital multimeter (DMM) - these two tools shouldn't cost you any more than $25 or $30, & they'll help you narrow the possibilities down quite a bit.

The noid light plugs into the injector harness instead of one of the injectors, & flashes when it gets the injector firing signal.

The DMM will let you know if each pink & orange wire has power when it's supposed to, & (using the resistance setting) whether or not you have infinite resistance -aka an 'open circuit'/broken wire. You can also check to see if any wires are shorted to ground with the continuity checking function, which sounds a tone when there's a direct electrical path from where you've placed one lead to the location of the other lead.

WARNING! - You want to be VERY CAREFUL about checking the resistance of any of the wires that are connected to the engine's ECM! It's entirely possible to damage or destroy the ECM by doing that, since the DMM itself introduces a voltage into the circuit. It would be a very good idea (IMHO) to learn about that before trying to do any troubleshooting with the DMM. Somewhere on the 'net there's a PDF version of GM's "LS1 engine swap handbook" that tells more about that. (Anyone have a link? My PC died, so I don't have it any more...)



To me, it sounds like it could be a couple of things, maybe three, each of which is working against you -

1 - The injectors are very likely "boogered up" with varnished fuel. dpd's suggestion "taking the injectors out and filling them with Seafoam and let them sit upright in a tray of Seafoam for a day or so and then blow them out with carb cleaner" is a good one, & won't cost much except a bit of time & effort.

2 - Since it worked before you re-routed your harness, go back & double-check, triple-check & even quadruple-check all of that. When troubleshooting a new issue, one of the best questions to start with is usually "What's changed recently??"

3 - Cam timing. When you installed the cam, did you guys do it right (actually degree it with a wheel), or did you just stab it in matching it dot-to-dot?? The latter method will frequently get it "close enough" to run, but you've got no way to know for sure exactly where it's at - and since it didn't run properly (it "had spark, back fires and it little bit of flames coming out of the short C6 Manifolds") even before you re-did the harness, I'd take a good hard look at the cam timing as a possible culprit as well.



Good luck! Take a methodical approach to it, rule out one thing at a time, & pretty soon you'll be hearing it roar through those shorty manifolds...

 

V8Rumble, thanks for your post and info provide, but I think I need to clear up a little bit of the info for my situation.

At this point I've never ran this engine. I started ordering parts for my 240sx conversion project in May and started building in June. I ordered my PCM from a Junk yard in Texas and it was shipped to another member here on the forums that reflashed the PCM, removed Vatts, all emissions and programmed it for the Z06 Cam. I repinned the truck harness with some of the writeups here on LS1tech as well as LT1swap.com. When I was referring to installing the Z06 Cam, that was when the engine was on my engine stand and I was building mounts. Now, I've removed and installed my engine about 9 times, but last week I thought it was the final install, when I realized the clutch line was leaking. I pulled then engine another time to fix the clutch and when it was out, I decided to unwrap my freshly finished wiring harness and rewrap it to get this best layout in my engine bay.

Update as for today, she's still not starting. Today we hooked up the noid light kit for the injectors and every injector pulsed as it should. We also, pulled the spark plug wires and verified that we do have spark. I hooked up my OBD2 port and the computer has Zero codes. We also, pulled the plugs and did a compression test on the engine. Every cylinder was between 155 and 160 psi. I put a noid light on the orange 12v battery wires and I have power at all times. I'm really stumped as to why my engine's not running. My neighbor even made a run out to a buddys house to get a better scan tool that would all us to veiw more details from the PCM. One thing that puzzeled me was that when looking through the Data listed on the scan tool it shows my timing as 0.0 degress. From what I've read isn't stock timing suppose to be around 14* or more. I think I read somewhere that the stock Z06 timing was at 22*. Could this be causing my issues and backfiring???

I'm thinking maybe I should find another PCM to borrow or something, to make sure it's not the issue. Anyone know if the PCM from my 03 Trailblazer would work. It's a Inline 6 so I highly doubt it.

Oh, and yes we did just install the Cam by lining up the Dots and making sure they match. I used a write up that was posted here on the forums for the swap, but I've done a few swaps before on DOHC engines and have never had a problem.

 

It is pretty unlikely that it is the PCM. If you really think this is a problem you should probably box it up and send it to whoever tuned it and have them check it.

If you are getting spark and fuel, then there are a couple things you should check.

Just because you are getting fuel doesn't mean your getting enough fuel. What's the pressure on the rail while you are trying to start it? It should be 52-53 psi continuous

Did you soak the injectors in seafoam as was suggested?

The cam swap bothers me. I'm not convinced the cam is correctly installed. I'd be less suspicious if you told us you fount TDC compression on No 1 cylinder and the cam degreed-in just fine.

 

Ok, well I have a fuel pressure gauge on hold for me right now at the local autozone. I will pick that up on the way home and check the pressure at the rail.

Does anyone know where I can rent or buy a timing degree wheel? I guess I will rip apart the front of the engine and check the timing. Again, I used the cam install guide here on the forums so I don't even know what degree the Cam should be set at. What timing would I need for this Z06 Cam???????

 

Also, I'm still thinking about this Cam install. Would I still be getting the compression numbers areound 155 - 160 if the Cam was not installed correctly. I would think that it wouldn't check out if the valves were opening early or late.

 

Well, pulled everything off the front of the engine and checked the timing. Timing looks perfect, I even called up my neighbor that's a mechanic and had him double check my work. Now, for the bad news. When driving the pulley back on to the Crank, the longer crank bolt that I bought shredded all it's threads in the Crank on the way out. From what we can see the Crank threading is fine, but I'm going to have to go buy a tap large enough to clean out the threads. Great day. I'm ready to push this car off a cliff.

On a side note, does anyone know if my backfiring and starting issues could be caused by my coil pack harness plugs being reversed? We were trying to think of what could cause these issues and it seems to be timing related, but I thought it might be possible that those plugs could be plugged in wrong. Our thoughts were that it the plugs where reversed the ignition coils would fire 1-8-7-2-5-6-3-4 instead of 1-8-7-2-6-5-4-3. Does that sound reasonable?

 

I don't know how many other ways to say this, but get a meter and a schematic and start tracing the ignition to PCM wires.

Download the schematics here-

http://www.autozone.com/autozone/rep...00c15280248067

-Buy a cheap meter, an analog one is best or a digital one that beeps when you have continuity,

-Disconnect the harness connector at the PCM and ignition packs

-Set the meter on resistance (Ohms)

-Check to see if you have the right wire going to the right place by making sure the pin numbers/colors correlate between the two harness connectors.

This should take you five minutes tops to find if you've got the coil packs reversed, or there is some other ignition related wiring problem

 

You said your crank & cam sensor looked the same & mixed them up. Mine on my 6.0 were different, one was a lot longer than the other. Man
Mabe check into that.

 

Ok, I'm pumped again. Finally figured out why the car wasn't starting and it was because the freaking ignition coil plugs where hooked up backwards. Driverside plug connected to Passengerside bank and vice versa. Swapped them and she fired right up. Ok, I took a really short crude video, because it was 8:30pm in my Neighborhood. Video was taken with my digital Camera so excuse the quality, I have one on my Mini dv, but for some reason I can't load to my PC.

Oh, and it's with Open C6 Manifolds, so the Beast is LOUD. It acutally scared me at first so if you see the car stumble it's because I was shutting her back off, because I thought I broke something. Lol, I've never been that close to car with open manifolds before.

http://www.youtube.com/watch?v=XG4JWYddBMA

 

I am doing a similar swap with an L33 to a Miata.

I was interested in your post as I just received a LS2 ('01 Z06) cam to replace the Silverado's stock cam.

Can you tell me if the cam swap was as simple as it appears?

Congrates on the engine firing!!


Thanks!